Life Sciences Commons^™

The Effects Of Intracerebroventricular Leptin On Milk Availability In Lactating Rats, Brittany Lynita Moore

Electronic Theses and Dissertations

Reports have linked energy balance along with adipocyte derived leptin action to improved fertility. Recent evidence indicates that leptin hormone is present in breast milk and leptin receptors are well expressed in mammary epithelial cells. The hypothesis that insufficiency of leptin restraint in the hypothalamus may underlie infertility in rodents and the failure of lactating breast to express adequate amount of milk was tested. Female Sprague-Dawley rats were injected leptin through intracerebroventricular cannulation (ICVC) of the third ventricle. Female rats were mated with stud males and observed throughout gestation. Compared to the control groups, leptin treatment increased prolactin levels in …

Distribution And Social Structure Of An Estuarine Bottlenose Dolphin (Tursiops Truncatus) Population In Northern South Carolina, Jamie L. Brusa

Electronic Theses and Dissertations

Information regarding habitat preference of apex predators may pinpoint areas dense in resources such as prey species. Knowledge of how animals use their habitat can enable the classification and targeted management of important habitat features. This study was conducted to determine the distribution and social structure of an inshore population of bottlenose dolphins within the North Inlet-Winyah Bay estuary in northern South Carolina. Photo-identification surveys were conducted along defined transect routes. Home ranges of individual dolphins were calculated using the minimum convex polygon method and the fixed kernel density method using Geographic Information System (GIS) software. Mean group sizes and …

Assessment Of Land Use And Neotropical Herpetofauna Along Steep Gradients Of Elevation In An Ecuadorian Ramsar Wetland Site #1143, Nicholas K. Henke

Electronic Theses and Dissertations

Using a comparative ecological approach, over the course of 18 days at the transition from a particularly wet to dry season in 2010, I assessed herpetofaunal assemblages and related abiotic parameters (i.e., photosynthetically active radiation, specific conductance, temperature and coarse woody debris) between contiguous forest and human impacted areas along three paired transects across the steep elevation gradient at Laguna de Cube, Ramsar site # 1143. Visual encounter surveys were used to capture herpetofauna with species being processed (e.g., weight, digit length, photographed) and identified to the lowest taxonomic level possible. After evaluating transect data for pooling (i.e., no significant …

Winter Site Fidelity In Secretive Marsh Sparrows Along The Coast Of South Carolina, Susan M. Shaw

Electronic Theses and Dissertations

Salt marshes, which are threatened by sea level rise and development, provide habitat for a distinctive suite of specialized vertebrates, and knowledge of the life histories of salt marsh specialists may help preserve salt marsh fauna in the face of change. I studied wintering site fidelity of Seaside (Ammodramus maritimus), Saltmarsh (A. caudacutus) and Nelson's (A. nelsoni) Sparrows by mist-netting and banding birds at six sites in two salt marshes in South Carolina. I banded 261 sparrows over two winters, 2009-2010 and 2010-2011, and recaptured 92. Across-year return rates were high, but significantly different across species: 43% for Seaside, 63% …

Population Dynamics Of The Sub-Arctic Copepod Calanus Finmarchicus In The Gulf Of Maine: Demography And Mortality Estimation, Cameron R. S. Thompson

Electronic Theses and Dissertations

Calanus finmarchicus is a widely distributed copepod species that dominants the zooplankton community in the Gulf of Maine. It is of particular interest in its role as a major food source for the endangered northern right whale and stocks of herring, mackerel and cod. More accurate coupled models to predict its distribution requires better life history models. However, due to the difficulty in estimating it, mortality is often used as a closure term in those models; the value is justified mathematically rather than ecologically. Instantaneous mortality is difficult to measure, but the Vertical Life Table method (VLT) has gained some …

Gentrification And Vulnerability Of Maine Fishing Communities, Cameron R. S. Thompson

Electronic Theses and Dissertations

Maine hosts numerous small fishing villages that contribute greatly to the States economy and culture. The cumulative effects of state and federal regulation, stock depletion and other socio-economic trends threaten these communities. Drawing on ethnographic research and interviews, we examine how gentrification is affecting the vulnerability and resilience of fishing communities. This study has revealed gentrification to be a complex process, which is merely the most readily recognizable symptom of forces that are reshaping the post-industrial landscape. Fishing communities can no longer be thought of as discrete entities isolated from broad social and economic changes. Technology and new markets have …

Responses Of Atlantic Salmon Stream Communities To Marine-Derived Nutrients, Margaret Quinn Guyette

Electronic Theses and Dissertations

This research examined responses of Atlantic salmon ( Salmo salar) stream communities to experimental simulation of marine-derived nutrient input. Prior to construction of dams beginning in the early 1800s, Atlantic salmon and other anadromous species migrated from the ocean to spawn in Maine's extensive rivers and streams. Spawning fish transported marine-derived nutrients to these systems as carcasses, eggs, and waste products. These contributions may have influenced productivity in otherwise nutrient limited systems, bolstering growth and survival of young Atlantic salmon and other anadromous species and influencing other components of the stream communities.

This study involved a reach-scale experiment to explore …

Biogenic Amine Levels Correlate With Time Of Day, Age, Light Cycle, And Aggressive State In The Flesh Fly, Sarcophaga Crassipalpis, Veronica L. Fregoso

Electronic Theses and Dissertations

The biogenic amines serotonin (5HT), dopamine (DA), and octopamine (OA) have been indicated in the regulation of behaviors, including aggression. The flesh fly, Sarcophaga crassipalpis, was used to investigate ontogenetic and circadian changes in amines and aggression. Heads of male flies were analyzed for amine content using high performance liquid chromatography with electrochemical detection (HPLC-ECD) at 3 time points on each of 4 consecutive days in 2 light cycles, 12:12 LD and 15:9 LD. Both DA and OA levels decreased with age. Light-cycle dependent differences were observed for all amines in overall levels and patterns of change throughout the …

Analysis Of Extracellular Proteins Expressed By Host, Crassostrea Virginica And Pathogen, Roseovarius Crassostreae In Roseovarius Oyster Disease, Erin Macro

Electronic Theses and Dissertations

Roseovarius Oyster Disease (ROD) involves the colonization of the inner shell of the Eastern Oyster (Crassostrea virginica) by the marine alpha-proteobacterium Roseovarius crassostreae. The ensuing disease can result in upwards of 90% mortality in hatchery-raised juvenile (< 25 mm shell length) oysters. Symptoms of ROD include heavy, brown ring deposits of conchiolin on the surface of the shell, as well as uneven valve growth and shell curvature. Although the bacterium does not invade oyster tissue or digestive tract, fluorescent localization of an R. crassostreae biofilm on the inner shells of ROD-affected oysters, and toxic effects of R. crassotreae extracellular products on hemocytes and larval oysters suggest that a chemical warfare takes place between the R. crassostreae biofilm and the oyster host. In this thesis, I cultured R. crassostreae under laboratory conditions and analyzed the affects of physical growth condition, temperature, culture volume, and iron limitation on bacterial growth and bacterial extracellular protein (ECP) production. Culture growth rate increased with increasing temperature. Iron limitation resulted in slower growth but had no affect on maximum culture density. Iron limited cells produced a greater volume of ECPs, especially at low cell density. ECPs from liquid and solid-phase cultures were analyzed by LC-tandem mass spectrometry. The resulting protein sequences had high similarity to proteins in other bacterial species that act as virulence factors in other hosts, including metal transporters (2), proteases (2) and a surface-associated GroEL chaperonin. I also exposed live oysters to ECPs of live R. crassostreae cells by embedding a filter capsule into the oyster shell. I sampled extrapallial fluid from oysters pre-exposure and post-exposure and analyzed the relative expression of the oyster defense protein dominin in addition to the extent of brown shell deposition as a function of bacterial presence. The injury response due to capsule embedment masked any potential response by oysters to R. crassostreae ECPs.

Characterization Of Fhua 104/149c: A Double Cysteine Fhua Mutant With Normal Binding And Diminished Transport, Ada K. Hagan

Electronic Theses and Dissertations

Iron is an essential element for most bacteria and is commonly acquired by siderophores, molecules secreted under iron restricted environment to bind ferric iron. Gram negative cells actively uptake these complexes via outer membrane-transport proteins such as FhuA in Escherichia coli. Structural analysis of receptors revealed a conserved β-barrel occluded by an N-terminal plug domain. The cell membrane TonB/ExbB/ExbD complex presumably supplies energy via interaction between the FhuA N-terminal TonB box and the C-terminal domain of TonB. In order to better understand the mechanism of action the FhuA mutant 104/149C, tethering the central β-strands 4 and 6 of the …

The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self

Electronic Theses and Dissertations

The ability to efficiently move over uneven terrain is critical for most terrestrial animals. Bipedal running is common in lizard species, however the biological advantage of a bipedal running posture remains uncertain. I examined the hypothesis that a bipedal posture is advantageous when crossing obstacles. Particularly, I determined whether kinematic adjustments differ among four focal species with contrasting body forms and ecology. I also examined how sprint speed changed when crossing obstacles with a quadrupedal versus a bipedal posture. I quantified kinematics from high-speed video (300 frames/second) of lizards running down a 3m runway both with and without the presence …

Role Of Provisions And Season On Foraging And Female Dominance Behavior In Ring-Tailed Lemurs (Lemur Catta) On St. Catherine's Island, Timothy Moore

Electronic Theses and Dissertations

Madagascar is undergoing habitat destruction and degradation that is threatening its unique species, including ring-tailed lemurs. Ring-tailed lemurs (Lemur catta) live in matriarchal groups composed of a dominant female, adult males, subadult males and females, and young. Due to their dominance, it has been suggested that female ringtailed lemurs have access to the highest quality resources and can monopolize food patches. Lemurs on St. Catherine's are free ranging and have unlimited access to natural food sources, but they are also provisioned with supplementary food to ensure a balanced diet. My study aimed to determine the impact of provisions on female …

Spatial And Temporal Immune Response In House Flies In Response To Ingestion Of Bacillus Cereus And Eschericha Coli 0157-H7, Adam Fleming

Electronic Theses and Dissertations

House flies (Musca domestica L.) feed and breed on septic substrates, putting them in direct contact with a multitude of disease causing agents and can act as a bridge for those agents to humans. The house fly has previously been shown to carry many different species of bacteria that are pathogenic. Escherichia coli O157:H7 is a pathogenic enterohemorrhagic serotype of E. coli that can be vectored by the house fly. Bacillus cereus is a foodborne pathogen that has also been isolated from the house fly in previous studies. To examine vector potential for these pathogens, house flies were fed green …

Predation Risk And Colony Structure In The Pea Aphid, Acyrthosiphon Pisum, Carl Nicolas Keiser

Electronic Theses and Dissertations

Many organisms live in transient or permanent aggregations to reduce individual predation risk. Hamilton's "Selfish Herd" theory states that an individual should assume a central position within a group to decrease individual predation risk relative to that of its neighbors (i.e., individuals should be selfish). This theory, however, cannot predict the spatial distribution of individuals within clonal aggregations, that is, when individuals are genetically identical (the "evolutionary self"). As aphids (small, herbivorous insects) are parthenogenetic, emit alarm signals, and have high levels of phenotypic plasticity to cope with environmental stressors like predation risk, they are a model organism for investigating …

Bird Use Of Cumberland Island's Freshwater Wetlands, Lisa Dlugolecki

Electronic Theses and Dissertations

Cumberland Island is the southernmost barrier island off the coast of Georgia. Its freshwater wetlands are an important, rare habitat to have on a barrier island surrounded by saltmarsh and ocean. Many species of birds require freshwater wetlands as feeding, roosting and nesting grounds. However, the freshwater wetlands on Cumberland Island have been impacted by humans for centuries causing birds to abandon their historic nesting ground. Known land use histories of Cumberland Island's freshwater wetlands were gathered to try and determine how the wetlands changed over time Wetlands were analyzed for presence of wetland-dependent birds and recorded. Thirty-six species of …

Patterns Of Chemosensory Behavior In A Closed Population Of Wild African Elephants (Loxodonta Africana), Russell W. Blogg

Electronic Theses and Dissertations

Chemosensory behaviors are used by many mammalian species to assess chemical signals in the environment. These chemical signals may contain important information about reproductive state, identity, status, or location of conspecifics. Elephants are a long-lived species and males reproduce at a much later age than females, which provides a protracted developmental period for males. This study examined chemosensory behaviors in a population of African elephants living in Addo Elephant National Park, South Africa and demonstrated that patterns emerge as elephants develop and approach sexual maturity. Older pubescent males (15-19 year olds) performed more chemosensory behaviors than younger pubescent males (10-14 …

Net Impulse And Net Impulse Characteristics In Vertical Jumping, Satoshi Mizuguchi

Electronic Theses and Dissertations

The purpose of this dissertation was to explore the potential use of net impulse and its characteristics in vertical jumping to monitor athletes' performance status and responses/adaptations to interventions. Five variables were proposed as net impulse characteristics: net impulse height and width, rate of force development, shape factor, and net impulse proportion. The following were then examined: 1) test-retest reliability of a new approach to identify net impulse in a force-time curve and of net impulse characteristics and criterion validity of the new approach; 2) effective measures of net impulse characteristics; 3) relationships between training-induced changes in its characteristics and …

Cell-Matrix Adhesion In Muscle Development And Disease, Michelle F. Goody

Electronic Theses and Dissertations

A variety of diseases, both inherited and acquired, affect muscle tissues in humans. The anchoring of muscle fibers to their surrounding environment is critical for muscle homeostasis. Muscle fibers attach to their microenvironment through cell-matrix adhesion complexes. These anchoring complexes are placed under repeated stress during muscle contraction. Genetic mutations in these complexes weaken the attachment between muscle fibers and their microenvironment, making fibers more susceptible to damage and death. This increased fiber degeneration eventually leads to progressive muscle wasting diseases, known as congenital muscular dystrophies. Although clinical trials are ongoing, there is presently no way to cure the loss …

Characterizing Fish Assemblage Structure In The Penobscot River Prior To Dam Removal, Ian Andrew Kiraly

Electronic Theses and Dissertations

The Penobscot River drains the largest watershed in Maine, and once provided spawning and rearing habitats to at least 11 species of diadromous fish. The construction of dams blocked migrations of these fish and likely changed the structure and function of fish assemblages throughout the river. Further alteration to fish assemblage structure likely occurred as a result of habitat fragmentation and alteration. The proposed removal of two main-stem dams, improved upstream fish passage at a third dam, and construction of a fish bypass on dam obstructing a major tributary is anticipated to increase passage of diadromous and resident fishes. To …

Application Of Multivariate Statistical Methodology To Model Factors Influencing Fate And Transport Of Fecal Pollution In Surface Waters, Kimberlee K. Hall

Electronic Theses and Dissertations

Degraded surface water quality is a growing public health concern. While indicator organisms are frequently used as a surrogate measure of pathogen contamination, poor correlation is often observed between indicators and pathogens. Because of adverse health effects associated with poor water quality, an assessment of the factors influencing the fate and transport of fecal pollution is necessary to identify sources and effectively design and implement Best Management Practices (BMPs) to protect and restore surface water quality. Sinking Creek is listed on the State of Tennessee’s 303D list as impaired due to pathogen contamination. The need to address the listing of …

Modeling Individual Tree And Snag Dynamics In The Mixed-Species Acadian Forest, Matthew B. Russell

Electronic Theses and Dissertations

Forest growth modeling has a long tradition of development and application in even‐aged stands targeting single-species plantations. Modeling efforts in mixed-species stands that contain uneven‐aged stand structures are much more recent. Serving as a transitional zone between the boreal and eastern broadleaf deciduous forest types, the Acadian Forest found throughout Maine and the Canadian Maritime Provinces is host to a wide variety of tree species that form complex stand structures. This study validated existing and developed component equations that comprise a widely-used individual tree growth and yield model in the northeastern US and Canadian Maritime provinces. An assessment of deadwood …

Analyzing The Interaction Between Melanocortin 5 Receptor, Melanocortin Receptor Accessory Protein 1, And Melanocortin 2 Receptor In Rainbow Trout, Domicinda M. Hill

Electronic Theses and Dissertations

Using CHO cells we sought to explore and characterize the functional relationship of rainbow trout MC5 receptor (rtMC5R) with zebrafish MRAP1 (zfMRAP1) and rainbow trout MC2 receptor (rtMC2R), as well as how the effect of such relationships may play a significant role in Hypothalamic-Pituitary-Adrenal/Interrenal axis activation. This research demonstrated that rtMC5R can be successfully expressed and functionally activated in CHO cells and, in a manner similar to mammals, α-MSH is the preferred ligand for rtMC5R. The presence of MRAP1 does not seem to inhibit the expression or function of rtMC5R, rather it appears that it may increase expression and total …

Connexin-32 And Connexin-43 Immunoreactivity In Rodent Taste Buds, Amanda E. Bond

Electronic Theses and Dissertations

Studies indicate that ATP is one of the primary neurotransmitters in taste transduction. ATP release occurs from taste cells via specific hemichannels such as pannexin/connexin hemichannels (Huang et al., 2007; Romanov et al., 2007). We hypothesize that Type II (receptor) and possibly Type III (presynaptic) cells release ATP at sites containing pannexin/connexin hemichannels. In this study, we examine the presence of connexin–32–LIR (Like Immunoreactivity) and connexin–43–LIR in rodent taste buds through immunocytochemical analysis and DAB (Di–amino–benzidine) immunoelectron microscopy. We observed that connexin–32–LIR co–localizes with P2X2–LIR in nerve fibers and in a small subset of NCAM–LIR cells. Connexin–32–LIR does not co–localize …

Phylogeny Of Panthera, Including P. Atrox, Based On Cranialmandibular Characters, Leigha M. King

Electronic Theses and Dissertations

Over the past 20 years both morphological and molecular phylogenies have been proposed for extant and extinct members of the family Felidae. However, there remain several discrepancies, particularly within the genus Panthera and the position of Panthera atrox. Consequently, morphologic characters from the skull and dentary were analyzed within Panthera (including all extant and one extinct taxa) to gain a better understanding of pantherine phylogeny. Multiple specimens of each taxon were analyzed, including: P. leo, P. tigris, P. onca, P. pardus , Uncia uncia, and Neofelis nebulosa. Four outgroups were used; Crocuta crocuta, Metailurus ssp., Proailurus lemanensis …

An Investigation Of Bacterial Ribonucleases As An Antibiotic Target, Ashley Denise Frazier

Electronic Theses and Dissertations

Antibiotics have been commonly used in medical practice for over 40 years. However, the misuse and overuse of current antibiotics is thought to be the primary cause for the increase in antibiotic resistance.

Many current antibiotics target the bacterial ribosome. Antibiotics such as aminoglycosides and macrolides specifically target the 30S or 50S subunits to inhibit bacterial growth. During the assembly of the bacterial ribosome, ribosomal RNA of the 30S and 50S ribosomal subunits is processed by bacterial ribonucleases (RNases). RNases are also involved in the degradation and turnover of this RNA during times of stress, such as the presence of …

The Influence Of Anadromous Alewife On Maine Lakes And Streams: Using Nutrient Limitation Assays And Stable Isotopes To Track Marine-Derived Nutrients, Katie G. Norris

Electronic Theses and Dissertations

Anadromous fish can act as nutrient subsidies to freshwater ecosystems when they return there to spawn. However, relatively few studies have quantified the role of alewife (Alosa pseudoharengus) as an ecologically important source of marine-derived nutrients (MDN) to lakes and streams. Primary producers in lakes and streams are often limited by nutrients, such as nitrogen and phosphorus. If alewife bring nutrients to lakes and streams, then the limitation of primary producers in those systems should be alleviated. Nutrient limitation assays and stable isotopes were used to examine the effects of alewife MDN on Maine lakes and their outlet streams. Nutrient …

Forest Fragmentation Patterns In Maine Watersheds And Prediction Of Visible Crown Diameter In Recent Undisturbed Forest, Brianne Elizabeth Looze

Electronic Theses and Dissertations

Extensive harvesting practices coupled with major ownership change have led to increasing fragmentation of Maine’s forest, a reduction from larger, contiguous mature forest patches into smaller patches. Using Landsat Thematic Mapper (TM) - based forest cover and change maps (1991-2007), fragmentation metrics, and Principal Components Analysis (PCA), this study determined the extent and configuration of forest fragmentation within three ecoregions and 186 level 5 watersheds throughout the state of Maine. Forests in the Northeastern ecoregion had higher harvest rates and more interspersed patches of undisturbed forest. Forests in the South-Central ecoregion are composed of more, smaller patches than their Northeastern …

Remote Estimation Of Regional Lake Clarity With Landsat Tm And Modis Satellite Imagery, Ian M. Mccullough

Electronic Theses and Dissertations

Water clarity is an ideal metric of regional water quality because clarity can be accurately and efficiently estimated remotely on a landscape scale. Remote sensing of water quality is useful in regions containing numerous lakes that are prohibitively expensive to monitor regularly using traditional field methods. Field-assessed lakes generally are easily accessible and may represent a spatially irregular, non-random sample. Remote sensing provides a more complete spatial perspective of regional water quality than existing, interest-based sampling; however, field sampling accomplished under existing monitoring programs can be used to calibrate accurate remote water clarity estimation models. We developed a remote monitoring …

Cloning, Expression, And Biochemical Characterization Of Recombinant Putative Glucosyltransferases Clone 3 And 8 From Grapefruit (Citrus Paradisi), Deborah Hayford

Electronic Theses and Dissertations

The grapefruit plant, Citrus paradisi, tends to accumulate high levels of flavonoid glycosides such as flavanones and flavones. Flavonoids have a vast array of important functions in plants and also in humans. Glucosyltransferases (GTs) are enzymes responsible for glucosylation reactions. In our pursuit to study the structure and function of flavonoid GTs, we have used molecular approaches to identify, clone, express, and functionally characterize the enzymes. This research was designed to test the hypothesis that PGT3 is a flavonoid glucosyltransferase and is subject to biochemical regulation. PGT3 has been tested for GT activity with compounds representing subclasses of flavonoids …

Cloning, Heterologous Expression In Yeast, And Biochemical Characterization Of Recombinant Putative Glucosyltransferase Clones 9 And 11 From Grapefruit (Citrus Paradisi), Anye Wamucho

Electronic Theses and Dissertations

Flavonoids are plant secondary metabolites that play diverse roles in plants and human health. These compounds in most part exist in the glucosylated form. Grapefruit accumulates high levels of glucosylated flavonoids. Plant secondary product glucosyltransferases (GTs) catalyze the glucosylation reaction, but due to low homology at both the nucleotide and amino acid sequence level of different GTs, it is not possible to ascribe function based on sequence only. The hypotheses that PGT clones 9 and 11 are plant secondary product GTs and are biochemically regulated were tested. PGT 9 has been cloned into Pichia pastoris using the pPICZA and pPICZAα …